Add optimization docs, workspace lints, and pre-commit hooks

- Add docs/OPTIMIZATIONS.md: catalog of 14 optimization passes with
  status tracking and implementation roadmap
- Configure workspace-level clippy and rustc lints in Cargo.toml
- Add clippy.toml and deny.toml for clippy thresholds and dependency
  auditing (licenses, advisories, bans)
- Set up pre-commit hook: cargo fmt, dprint, clippy, cargo deny,
  cargo machete
- Update Justfile with deny/machete targets, dprint in fmt checks

crates/core/Cargo.toml

@@ -5,6 +5,9 @@ version.workspace = true
 edition.workspace = true
 license.workspace = true
 
+[lints]
+workspace = true
+
 [dependencies]
 wasm-encoder = { workspace = true }
 wasmparser = { workspace = true }